In recent years, there has become widespread a method by which, when video data and audio data, acquired by shooting or the like, are recorded onto a recording medium, additional information, such as editing information, is added to the video data and the audio data (e.g., see patent document 1).
For example, in the case where video data and audio data are recorded onto videotape by a VCR or the like, as shown in FIG. 1A, the audio data and the video data (skewed black rectangular portions in FIG. 1A) are in turn recorded in an essence data recording area 11 which is a predetermined recording area on videotape 10 and also LTC (Linear Time Code), associated with the video data, which is a time code of each frame of the video data, is recorded in an additional-information recording area 13 which is a predetermined recording area.
In the case of FIG. 1A, three clips (clips 12-1 to 12-3), including the video data and the audio data, are recorded in the essence data recording area 11 on the videotape 10, and LTC, associated with the clips, is recorded in the additional-information recording area 13. The values of the first LTCs 14-1 to 14-3 of LTCs associated with the clips 12-1 to 12-3 are “00:10:20:00”, “12:34:56:10”, and “00:00:30:15”, respectively.
LTCs are continuous in each clip. However, there are cases where LTCs are discontinuous over clips, or there are cases where LTCs having the same value exist in a plurality of clips.
In recent years, a method of non-linear editing (NLE), to perform editing with a personal computer or the like, has been employed as a method for editing video data and audio data. In the non-linear editing, as shown in FIG. 1B, video data and audio data are recorded as files in units of clips, for example, on a hard disk (HDD) 20 or the like in a personal computer used as a data editing apparatus.
In the case of FIG. 1B, essence data, which is data to be edited including video data and audio data is recorded on the hard disk 20, as files 21-1 and 21-2. In this case, it is possible to specify essence data in units of frames, for example, and each frame has a frame number assigned thereto in each file. This frame number is managed as FTC (File Time Code), and a user who edits essence data can directly specify a necessary part in a necessary file using the FTC.
The FTC (frame number) is relative position information in which, the number of the first frame of each file being “0”, FTC is assigned to each frame in order from the first frame. Therefore, there are cases where FTC (frame number) of the same value exists in a plurality of files.
[Patent document 1] Japanese Patent Application Laid-Open No. 2001-29241 (pages 14 and 15, FIG. 8)